Isaiah 66:16 says, “The slain of the Lord will be many,” and what follows is a description of the Last Judgment. This is not a nuclear holocaust, but rather Armageddon. The Lord will slay His enemies, and then He shall execute the Last Judgment.
For see how YHWH comes in fire,
His chariots like the tempest,
to assuage His anger with burning,
His threats with flaming fire.
For by fire will YHWH execute judgment
and by His sword against all mankind.
The victims of YHWH will be many. —Isaiah 66:15-16
In my opinion this is a description of global nuclear war, and that war is our Creator’s means of executing His judgment on humanity. And it is a judgment that we well deserve since by building our arsenals of ICBMs we have grossly violated His two primary commandments: to love Him and to love our neighbors.
Chariots are vehicles of war, and “chariots like the tempest” refers to ICBMs being launched. The word “tempest” also occurs in Jeremiah:
See! The disaster spreads
from nation to nation.
A mighty tempest rises
from the far ends of the earth. --Jeremiah 25:32
This passage describes the beginning of the coming global nuclear war. The “mighty tempest” is the mass launching of ICBMs from opposite sides of the earth.
Jeremiah 25:33 notes the aftermath of WW III:
Those slaughtered by YHWH that day will be scattered across the world from end to end. No dirge will be played for them; no one will gather them or bury them; they will stay lying on the ground like dung.
—Jeremiah 25:33
With all due respect to the CCC, the fire of Luke 12:49 is not the benign fire of the conversion or faith, but is the same as the fire of Isaiah 66:15-16. It is the fire of global nuclear war.
I have come to bring a fire to the earth, and how I wish it were blazing already! —Luke 12:49
Jesus said these words as He agonized over His imminent torture which He know would be demanded by the Temple priests. The immediate advent of the fire of Isaiah would have spared Him from that terrible event.